Incandescent lamp.



Patented June 19, I900.

m j a,

l KITSEE INCANDESCENT LAMP.

{Application filed Mar. 2, 1900.)

No 65l,866

(No Model UNITED STATES PATENT OFFIC ISIDOB KITSEE, OF PHILADELPHIA,PENNSYLVANIA.

lNCAND ESCE NT LAMP.

SPECIFICATION forming part of Letters Patent No. 651,866, dated June 19,1900.

Application filed March 2, 1900.- Serial No. 7,107. (No model.)

To all whom it may concern:

Be it known that I, ISIDOR Krrsnn, of the city and county ofPhiladelphia,State of Pennsylvania, have invented certain new and usefulImprovements in Incandescent Lamps, of which the following is aspecification.

My invention relates to an improvement in incandescent lamps,and hasmore special reference to incandescent lamps wherein a material is usedcapable of conducting the electric current when heated. In these lampsthe pencil designed to become incandescent consists generally of an oxidof one of the rare metals, such as zirconium, thorium, yttrium, cerium,&c. Even though there is a great advantage in the economy of electriccurrent c0nsumed,these lamps are not generally used, for the reason thatthe primary process of heating the filament has involved, so far, greatdifficulties; and the object of myinvention is to provide such lampswith means whereby the heating of the pencil or rod is automaticallyaccomplished.

Referring to the drawings, Figure 1 is a longitudinal section of thepencil embodying my invention. Fig. 2 is an enlarged crosssection of thepencil. Fig. 3 is an enlarged section of the switch for said pencil.Fig. 4 is a modification of said pencil.

A is the pencil; B B, the conductors to which said pencil is secured; OG, the circuitwires. D is a cavity formed through said pencil; E, theconductive material lining the walls of said cavity; F, a disk ofinsulating material forming the base of the switch; G, a casing for saidswitch; H, a stud screw which screws the contact-spring I to the base Fand also forms an electrical connection between the conducting-film Eand the spring I.

J is a contact-spring secured to the base F by the screw K, which screwalso extends into the terminal B, thereby forming an electricalconnection between the pencil A and spring J.

L is a contact-spring secured to the base F by the screw M, one of theleading-in wires being connected to the spring L. I Nis theswitch-block,upon which are formed the three faces 1 2 3.

O is the shank; P, the button for turning the switch-block.

The pencil is provided with the center groove. This groove is providedwith a 0011- ducting-layer of any suitable material; but I have foundthat if either carbon or any'of the baser metals in finely-divided stateis used the high temperature will destroy their usefulness after a veryshort time. In my endeavor to find a material capable of withstandingthis high temperature and observing its usefulness for a great length oftime I found that nearly the only material capable of being usedeconomically for the purpose in question is platinum in itsfinely-divided state. If platihum-black is used, the best way to applythe same is to slightly coat the inner walls of the cavity with a thinlayer of this material. The coating should be such as to offer acomparatively-large resistance to the passage of the current and yetshould allow a slight amount of current of a predetermined voltage topass after the switch has been closed. If the plati num is in solution,then the inner cavity should be filled with this solution and the pencilbe raised to a high enough temperature to evaporate this solution, andthereby coat the cavity with a slight film of the metal; but I preferthe first method, because the porosity of the pencil allows part of thesolution to penetrate the body of the same.

Instead of the center cavity the pencil may consist of two semicylindersthe straight surfaces of which are designed to come together and arecoated with the platinum.

The modus operandi is as follows: N ormally the switch is entirely open.If it is de sired to light the lamp, the switch is closed in a manner sothat the terminal of the current-carrying circuit 0 is in electricalconnection with the screw H, thereby establishin g a path for thecurrent consisting of the thin layer of platinum-black. A slight amountof current will flow and thereby raise the metallic film, as well as thenear-bylayer of the pencil proper, to a high temperature, which in ashort time will communicate itself to the entire pencil. As soon as thepencil has attained a sufficieut degree of temperature the switch isturned till the terminal of the circuit O is out of contact with thescrew H, but brought in electrical contact with the screw K, therebybreaking the circuit with the film and making the circuit through thepencil proper.

I am well aware that attempts have been ro venient.

made to provide temporarily a passage for the flow of the currentthrough pencils nonconducting at low temperatures; but the ,means fordoing so had to be repeated as often as the lamp was lighted. One ofthese x5 proper, and I have found that it is best to provide the innerpart of the pencil with such a conducting-path, as otherwise the same isliable to injury and to be destroyed by the heated atmosphere.

Having now described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

1. In an incandescent lamp, a pencil non conducting at low, butconducting at high temperatures, said pencil being provided with aslight layer of platinum-black.

2. In an incandescent lamp, a pencil nonconducting at low, butconducting at high temperatures, in combination with a conduct ing-filmconsisting of finelydivided platinum.

3. As an accessory, for an incandescent lamp, the pencil of which isnon-cond uctin g at low, but conducting at high temperatures, aconducting-film consisting of finely-divided platinum, substantially asand for the purpose specified.

In testimony whereof I hereby sign my name, in the presence of twosubscribing witnesses, this 26th day of February, 1900.

ISIDOR KITSEE.

Vitnesses:

E. R. STILLEY, H. B. ELDRIDG-E.

